XB-ART-22129Mol Cell Biol October 1, 1993; 13 (10): 5990-8.
A U3 small nuclear ribonucleoprotein-requiring processing event in the 5'' external transcribed spacer of Xenopus precursor rRNA.
A processing site has been identified within the 5'' external transcribed spacer (ETS) of Xenopus laevis and X. borealis pre-RNAs, and this in vivo processing can be reproduced in vitro. It involves a stable and specific association of the pre-rRNA with factors in the cell extract, including at least four RNA-contacting polypeptides, yielding a distinct complex that sediments at 20S. Processing also requires the U3 small nuclear RNA. This processing, at residue +105 of the 713-nucleotide X. laevis 5'' ETS, is highly reminiscent of the initial processing cleavage of mouse pre-rRNA within its 3.5-kb 5'' ETS, previously thought to be mammal specific. The frog and mouse processing signals share a short essential sequence motif, and mouse factors can faithfully process the frog pre-rRNA. This conservation suggests that this 5'' ETS processing site serves an evolutionarily selective function.
PubMed ID: 8413202
PMC ID: PMC364653
Article link: Mol Cell Biol
References [+] :
Bach, Sequence organization of the spacer in the ribosomal genes of Xenopus clivii and Xenopus borealis. 1982, Pubmed, Xenbase